{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T16:52:19Z","timestamp":1781110339555,"version":"3.54.1"},"reference-count":0,"publisher":"National Academy of Sciences","issue":"9","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[1971,9]]},"abstract":"<jats:p>\n                    Purified cell-free extracts of\n                    <jats:italic>Klebsiella pneumoniae<\/jats:italic>\n                    reduce N\n                    <jats:sub>2<\/jats:sub>\n                    , N\n                    <jats:sub>3<\/jats:sub>\n                    <jats:sup>-<\/jats:sup>\n                    , CN\n                    <jats:sup>-<\/jats:sup>\n                    , or C\n                    <jats:sub>2<\/jats:sub>\n                    H\n                    <jats:sub>2<\/jats:sub>\n                    in the absence of an ATP-generating system when substrate concentrations of ATP are used. The optimum Mg\n                    <jats:sup>++<\/jats:sup>\n                    \/ATP ratio is 0.5. Michaelis constants for the reduction of substrates calculated from kinetic studies of\n                    <jats:italic>K. pneumoniae<\/jats:italic>\n                    nitrogenase were similar to those that have been reported for\n                    <jats:italic>Azotobacter vinelandii<\/jats:italic>\n                    and\n                    <jats:italic>Clostridium pasteurianum<\/jats:italic>\n                    . Hill plots of the kinetic data are consistent with the view that there is a single binding site for each of the substrates N\n                    <jats:sub>2<\/jats:sub>\n                    , C\n                    <jats:sub>2<\/jats:sub>\n                    H\n                    <jats:sub>2<\/jats:sub>\n                    , CN\n                    <jats:sup>-<\/jats:sup>\n                    , N\n                    <jats:sub>3<\/jats:sub>\n                    <jats:sup>-<\/jats:sup>\n                    , and ATP. Inhibition studies of\n                    <jats:italic>K. pneumoniae<\/jats:italic>\n                    nitrogenase indicate that ADP competitively inhibits C\n                    <jats:sub>2<\/jats:sub>\n                    H\n                    <jats:sub>2<\/jats:sub>\n                    reduction. Also, the reducible substrates, N\n                    <jats:sub>3<\/jats:sub>\n                    <jats:sup>-<\/jats:sup>\n                    and CN\n                    <jats:sup>-<\/jats:sup>\n                    , inhibit C\n                    <jats:sub>2<\/jats:sub>\n                    H\n                    <jats:sub>2<\/jats:sub>\n                    reduction. The inhibition by azide is noncompetitive, that by cyanide is mixed.\n                  <\/jats:p>","DOI":"10.1073\/pnas.68.9.2016","type":"journal-article","created":{"date-parts":[[2006,5,31]],"date-time":"2006-05-31T02:30:31Z","timestamp":1149042631000},"page":"2016-2018","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":12,"title":["Kinetic Studies on\n                    <i>Klebsiella pneumoniae<\/i>\n                    Nitrogenase"],"prefix":"10.1073","volume":"68","author":[{"given":"R. A.","family":"Parejko","sequence":"first","affiliation":[{"name":"Department of Bacteriology, University of Wisconsin, Madison, Wis. 53706"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P. W.","family":"Wilson","sequence":"additional","affiliation":[{"name":"Department of Bacteriology, University of Wisconsin, Madison, Wis. 53706"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[1971,9]]},"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.68.9.2016","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,13]],"date-time":"2022-04-13T10:31:34Z","timestamp":1649845894000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.68.9.2016"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1971,9]]},"references-count":0,"journal-issue":{"issue":"9","published-print":{"date-parts":[[1971,9]]}},"alternative-id":["10.1073\/pnas.68.9.2016"],"URL":"https:\/\/doi.org\/10.1073\/pnas.68.9.2016","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[1971,9]]},"assertion":[{"value":"1971-09-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}